Test 2: Class Section C

Friday 12th May 1995

This test will be made up of three parts:

1. Debugging, running and testing a provided program.

2. Making use of the above program in the development of a new program and then testing this extensively.

3. Making minor alterations to the original program in order to improve the quality of the code, and/or to add additional functionality.

Note that marks will be awarded purely on the quality of the content of the final report. Therefore, at all stages of the test, please describe plans, algorithms, problems encountered, tests carried out and, when the required tasks have been completed, describe any conclusions drawn from the exercise.

Part 1 (40%)

The program POLARMUL.C in supposed to take in the rectangular co-ordinates of two complex numbers, convert them to polar and multiply them. The product is then printed to the screen in polar co-ordinates. There are, however, a number of errors in the program.

(a) Present a reformatted version of this program which demonstrates satisfactory practice for spacing, line breaking and indentation. Add comments where relevant to improve the understandability of the program.

(b) Correct any compiler / linker errors. In the case of compiler warnings, either resolve them or explain why they can be ignored.

(c) When the program compiles successfully, run it and establish the presence of any runtime errors. Correct these.

(d) Test the program extensively to ensure correct operation.

Part 2 (40%)

Refine the POLARMUL.C program by adding the following functionality:

1. The only variables which may be globally defined are modulus and theta - the values of all other variables should be passed between functions using parameters and/or return values as appropriate.

2. Write a function which converts the final solution back into rectangular co-ordinates, according to the formula:

   

   The product should now be printed to the screen in both polar and rectangular co-ordinates.

The following guidelines must be followed:

1. The program must remain divided into functions.

2. The program should demonstrate good coding practices with regard to spacing, comments etc.

3. Test this program rigorously and detail all results.

Part 3 (20%)

1. polarmul.c currently prints the argument of the solution in radians. Develop a function which converts this radian value to degrees and incorporate it into the program.

2. polarmul.c should not be restricted to multiplying two complex numbers only - alter it so that the user is initially prompted for the number of complex numbers to be entered and then that number are read in and multiplied, yielding a single product which is printed out.